An implant generally refers to a substitute that can substitute for a human tissue when an original human tissue is lost but refers to implanting an artificially made tooth in dentistry.
To place an implant, first, a perforation is formed in an alveolar bone using a drill and a fixture is placed in the perforation. The perforation formation and the implant placement are differently performed for each person to be treated. This is because a position, a depth, and a direction of an implant placement should be determined in consideration of various factors such as a state of a tooth of a person to be treated, a position of a tooth that requires an implant placement, a state of an alveolar bone of the person to be treated, or the like.
In this way, it is very difficult for an experienced person as well as an inexperienced unskilled person to accurately determine the depth and the direction in a drilling task for forming a perforation in an alveolar bone. Further, it is extremely difficult for an unskilled person to determine a depth of a perforation formed during drilling without a separate measurement step. Accordingly, an auxiliary tool referred to as a surgical guide is used to guide an accurate depth, position, and direction of a perforation.
A conventional surgical guide is manufactured through the following process. First, a 3D image of an inside of an oral cavity of a person to be treated is acquired by computerized tomography (CT) scanning, and a 3D exterior image of the inside of the oral cavity of the person to be treated is acquired through oral scan. Here, information related to a crown, a dental root inside the oral cavity, and a shape and bone density of an alveolar bone is included in the 3D image. Exterior information related to shapes of a crown and gum inside the oral cavity is included in the 3D exterior image.
When each of the images is acquired, the two images are matched on the basis of a set point inside the oral cavity such as abnormality of a tooth. Then, an implant placement plan is established through a matched result, and the surgical guide is manufactured according to the placement plan.
Here, the 3D exterior image is acquired by directly scanning the inside of the oral cavity of the person to be treated using an oral scanner, and there is a problem in that it is difficult to accurately acquire an image due to movement of soft tissues such as the tongue, the lips, and inner surfaces of cheeks.
That is, because an accurate scanning task is difficult due to movement of the tongue interfering with a scanning path of the oral scanner, a step of performing a correcting task for an acquired 3D exterior image is required, and time is required for the correcting task, there are problems in that an implant placement period increases and economic feasibility decreases. Also, it is difficult for an operator to accurately check an inside of an oral cavity of a person to be treated due to the person to be treated unconsciously moving his or her lips, a space and a path through which the oral scanner is moved are not sufficiently secured, and accuracy of an acquired image decreases.
Furthermore, because a soft tissue such as buccal mucosa substantially surrounds and is adhered to an outer portion of gum, it is difficult for the oral scanner to be inserted thereinto, and an unnecessary image of soft tissues is included in the 3D exterior image. Consequently, it is difficult to utilize the 3D exterior image as data for image matching when an outer shape of the soft tissue is included in the 3D exterior image, and there is a problem of causing an inconvenience to a person to be treated due to repeated oral scans.
Further, because a retracting tool capable of holding each of the soft tissues to prevent movement of the tongue and the lips is separately disposed, there are problems in that it is difficult for an operator to operate and the scanning task efficiency decreases due to requiring an assistant operator.
The 3D exterior image can be acquired when manufacturing dentures of a person to be treated who is edentulous or partially edentulous as well as when placing an implant.
Specifically, a fixing groove portion formed inside an oral cavity so that a denture is fitted thereto is designed on the basis of an outer profile of gum included in the 3D exterior image. Here, there is a problem in that design precision of the fixing groove portion decreases when the outer shape of the soft tissue is included in the 3D exterior image. Thus, there are problems in that reliability of masticatory efficiency decreases due to a manufactured denture being unable to be accurately installed inside an oral cavity of a person to be treated, and an inconvenience of the person to be treated increases due to pain in the gum during occlusion.